Bacterial community modifies host genetics effect on early childhood caries

Area of Science:

• Oral health research
• Microbiology
• Genetics

Background:

• Early childhood caries (ECC) affects approximately 20% of children by age five.
• Both oral microbiome and host genetics are implicated in ECC susceptibility.
• The interaction between the oral microbiome and genetic susceptibility to ECC remains largely unexplored.

Approach:

• A polygenic score (PGS) for primary tooth decay was developed using genome-wide association data.
• The association between PGS and ECC incidence was analyzed in a longitudinal birth cohort (n=783).
• The effect of salivary bacterial community state types (CST) on the PGS-ECC association was investigated in a subset (n=138).

Key Points:

• A high PGS for primary tooth decay was not directly associated with increased ECC rates.
• Cariogenic salivary bacterial CSTs at 24 months were strongly associated with ECC (OR: 7.48).
• A significant interaction (P=0.04) was observed between salivary bacterial CST and PGS, with PGS associated with ECC only in those with non-cariogenic CSTs.

Conclusions:

• Genetic risk factors for ECC may be masked without considering the oral microbiome.
• Preventing colonization by cariogenic oral bacteria offers a universally beneficial strategy for ECC prevention.
• Understanding the interplay between the oral microbiome and host genetics is vital for effective ECC management.